"The Cathedral" by J.K. Huysmans is a novel that follows the spiritual journey of a man named Durtal, who is struggling to find meaning and purpose in his life. The novel is a work of decadent literature, and it explores themes of faith, sin, and redemption. The novel is divided into two parts. In the first part, Durtal immerses himself in the study of the Middle Ages, with a particular focus on the life of Gilles de Rais, a 15th-century French nobleman, and serial killer. Through his research, Durtal becomes increasingly obsessed with the darker aspects of human nature, and he begins to question his own faith. In the second part of the novel, Durtal's spiritual crisis comes to a head as he visits various churches and monasteries, seeking guidance and enlightenment. Huysmans' writing is deeply introspective and psychological, as he explores the inner workings of Durtal's mind and soul.